Hi
Sorry am late to this.
My 2016 A4 2.0 Avant TDI is also registered as a B8 even though it is a B9 shape. The sticker on the door pillar also stated it is a 'B8' and as on the V5. This could be sticker errors on the first generation B9. When I first noticed this some 3 years ago, I did ask the Audi dealer to help get it changed but it didn't get anywhere so I have left it.